There are a wide variety of motionless or static-mixing element designs used within a flow passageway for fluid-mixing and -contacting problems. A typical static-mixing unit comprises a series of stationary, rigid, mixing elements placed lengthwise in a conduit, to form a plurality of intersecting channels which split, rearrange and recombine one or more component fluid streams into smaller and smaller layers, until there is one homogeneous stream as an outlet stream. Generally, such motionless or static-mixing elements are made from twisted helixes, offset-stacked corrugated sheets or intersecting bars or blades welded together, to form the desired open channels, which are placed end to end along a section of a pipe, to form a particular static- or motionless mixing unit. One or more fluid streams to be mixed enter the pipe and are split into individual streams in the defined channels, which channels provide strong transversal flow and fluid exchange at the pipe wall. Part of each channel intersection causes a part of the fluid to shear off into a crossing channel. Generally, adjacent mixing elements are positioned 90.degree. relative to each other, so that two-dimensional mixing takes place over the first static-mixing element, and three-dimensional mixing over all succeeding mixing elements.
Static-mixing elements and the method for preparing such elements, for the mixing of fluid streams, are described, for example, in U.S. Pat. No. 4,062,524, issued Dec. 13, 1977, hereby incorporated by reference. In this patent, pairs of comb-like plates are arranged, so that the webs of one plate extend crosswise through the slots of the other, and with the resulting mixing insert providing motionless mixing of fluid streams.
Static-mixing technology and static-mixing elements are described, for example, in Bulletin KSM-6, entitled "Static Mixing Technology" of Koch Engineering Company, Inc., 1991, hereby incorporated by reference. This publication describes, for example, a particular series of static-mixing element designs known as the SMX, SMXL and SMXL-R mixing elements, which are employed primarily in viscous mixing applications.
The static-mixing element designs, known as SMX, SMXL and SMXL-R (trademarks of Koch Engineering Company, Inc. of Wichita, Kans.), or similar mixing element designs, involving a plurality of flat-bladed, metal or plastic mixing elements, are generally prepared by stamping, nibbling, cutting or grinding individual blades, which are then shaped or bent to particular angles and welded, fastened or secured together, to form the static-mixing element. The entire mixing element also may be formed in one operation, such as by injection-molding with plastic, casting in metal, such as by the lost-wax process, metal-sintering, EDM-machining, or milling the static-mixing element shape from a solid block of material. Such blade-like, static-mixing elements, particularly when the mixing elements are about twelve inches in diameter or less; for example, one to three inches, are very difficult and time-consuming to manufacture and to assemble, and, consequently, are quite expensive. While large-diameter, blade-like, static-mixing elements may involve the same type of process, they are somewhat easier to manufacture, due to the larger size, but still the manufacture of the static-mixing elements tend to be time-consuming and expensive to fabricate.
It is, therefore, desirable to provide for a new and improved, low-cost, inexpensive, efficient method of manufacturing a metal, plastic, glass or ceramic static-mixing element or unit, and particularly, a flat, blade-type, static-mixing element or unit which is employed primarily in a laminar-flow or transitional-flow operation, in the mixing of high-viscosity liquids and fluids.